Gaza City (AFP) — Israel’s military said Monday it had killed four armed militants who emerged from a tunnel in southern Gaza and attacked its troops, accusing the suspects of a “blatant violation” of the ceasefire.

Despite a United States-brokered truce that entered its second phase last month, violence has continued in the Palestinian territory, with Israel and Hamas trading accusations.

Gaza’s health officials said that six people were killed on Monday by Israeli fire in several incidents separate to the one in Rafah, including four killed in an air strike on an apartment in Gaza City.

In a statement about the tunnel incident, the Israeli military said, “A short while ago, four armed terrorists exited an underground tunnel shaft and fired towards soldiers in the Rafah area in the southern Gaza Strip... Following identification, the troops eliminated the terrorists.”

It said none of its troops had been injured in the attack, which it called a “blatant violation of the ceasefire agreement.”

Israeli troops “are continuing to operate in the area to locate and eliminate all the terrorists within the underground tunnel route,” the military added.

Hamas’ armed wing described what it said was a “heroic resistance.”

The fighters “refused humiliation or submission in the besieged Rafah valley and chose martyrdom over surrender,” the Ezzedine al-Qassam Brigades said in a statement.

Hamas said in late November that dozens of its fighters were holed up in southern Gaza’s tunnels, beneath areas controlled by the Israeli military.

This was a sticking point in the early days of the ceasefire, with Israel insisting the militants posed a security threat, while Hamas sought safe passage for them.

Since then, many of the fighters have been killed in clashes with Israeli troops during operations targeting tunnels near Rafah, according to the military.

Rafah lies in an area held by Israeli forces following their withdrawal behind a so-called “Yellow Line” under the terms of the US-brokered ceasefire, in effect since 10 October.

Israeli troops still control more than half of Gaza, while the rest remains under Hamas authority.

The Israeli military has in recent weeks launched waves of strikes on Gaza over what it says are violations of the fragile truce.